High temperature adsorption isotherms on equilateral triangular terraces.
Within the context of a lattice–gas model, the adsorption isotherms on infinitely long equilateral triangular terraces are obtained at high temperature using a recently developed transfer matrix method. The computations, using long double precision arithmetic, are conducted for semiinfinite terraces with two different orientations, an increasing number M of atomic sites in their width, and without a periodic boundary. Our general formulation recovers the known results of the statistical average of the coverage and the entropy per site divided by Boltzmann’s constant, which is independent ofM and given by the onedimensional solution (M = 1).We report as new results the values of θ(M, θ0) and β(M,θ0), which are the statistical averages of the numbers of first and secondneighbors per site, respectively, as functions of the width M and the coverage θ0. These functions, when scaled according to their maximum values obtained at full coverage, both reduce to θ2 0 for all M. With this new information, we show that in the infiniteM limit, and at half coverage, the adsorbate occupational configuration exhibits repetitive hexagonal patterns.
Main Author:  Phares, Alain J. 

Other Authors:  Grumbine Jr, David W., Wunderlich, Francis J. 
Language:  English 
Published: 
2007

Online Access: 
http://ezproxy.villanova.edu/login?url=https://digital.library.villanova.edu/Item/vudl:179433 
Summary:  Within the context of a lattice–gas model, the adsorption isotherms on infinitely long equilateral triangular terraces are obtained at high temperature using a recently developed transfer matrix method. The computations, using long double precision arithmetic, are conducted for semiinfinite terraces with two different orientations, an increasing number M of atomic sites in their width, and without a periodic boundary. Our general formulation recovers the known results of the statistical average of the coverage and the entropy per site divided by Boltzmann’s constant, which is independent ofM and given by the onedimensional solution (M = 1).We report as new results the values of θ(M, θ0) and β(M,θ0), which are the statistical averages of the numbers of first and secondneighbors per site, respectively, as functions of the width M and the coverage θ0. These functions, when scaled according to their maximum values obtained at full coverage, both reduce to θ2 0 for all M. With this new information, we show that in the infiniteM limit, and at half coverage, the adsorbate occupational configuration exhibits repetitive hexagonal patterns. 
